Question: Simplify the following expression: $q = \dfrac{n}{8} - \dfrac{5n}{2}$
Answer: In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $8$ and $2$ $\lcm(8, 2) = 8$ $ q = \dfrac{1}{1} \cdot \dfrac{n}{8} - \dfrac{4}{4} \cdot \dfrac{5n}{2} $ $q = \dfrac{n}{8} - \dfrac{20n}{8}$ $q = \dfrac{n -20n}{8}$ $q = \dfrac{-19n}{8}$